Attachment for centerless grinder



Oct. 29, 1963 Filed Oct. 26, 1961 P. DERRICO ATTACHMENT FOR CENTERLESS GRINDER 3 Sheets-Sheet 1 INVENTOR PASQUALE D'ERR \co BY W 7 ATTORNEY Oct. 29, 1963 .P. DERRICO ATTACHMENT FOR @ENTERLESS GRINDER 3 Sheets-Sheet 2 Filed Oct. 26, 1961 IIII' IIFPLL INVENTOR PASQUALE D'ERRICO ATTORNEY United rates tpatent 3,103,411 ATTACHMENT F OR CENTERLESS GRINDER Pasquale DErrico, 31 J acltsen Place, Mconachie, NJ. Filed Get. 26, 1961, Ser. No. 147,775 8 Claims. (ill. 51-236) The invention relates to attachments for supporting work on centers.

A primary object of the invention is to provide an attachment which is adapted for use with a centerless grinder to enable the same to function also as an external grinder, whereby the capabilities of a centerless grinder may be greatly increased. When the attachment is removed from the machine, the centerless grinder can operate in a conventional manner. When the attachment of the invention is used, the external grinding is performed by the centerless grinder, thereby retaining the advantages of centerless grinding, advantages which are not available with conventional external grinding machines.

Another object of the invention is to provide an attachment which can be received by a conventional centerless grinder without requiring any modification of the centerless grinder, except merely to provide the machines Workrest with tapped holes.

A further object of the invention is to provide an attachment which enables a workpiece to be rapidly and conveniently changed for another without disturbing the machine or attachment setting, thereby permitting the large output normally associated with a centerless grinder.

Still another object of the invention is to provide an attachment capable of accommodating workpieces of widely diiferent sizes.

An additional object of the invention is to provide a simple, rugged attachment capable of withstanding all stresses occurring during operation of the machine, and requiring no special training or skill in the use or" the attachment.

Still a further object of the invention is to provide an attachment for a centerless grinder which afiords the operator with the necessary measure of safety when the attachment is on the machine to furnish external grinding.

These, and other objects, advantages, and improved results will be apparent from the following detailed description, taken in conjunction with the drawings, in which:

FIG. 1 is a perspective view of an attachment according to the invention as viewed from the rear, the work and some parts of a centerless grinding machine being shown in phantom;

FIG. 2 is a side elevational view of the attachment;

FIG. 3 is a vertical sectional view taken approximately in the plane of line 33 of FIG. 1, this view showing a. detent structure in one position;

FIG. 4 shows the detent structure of FIG. 3 in a different position;

FIG. 5 is a vertical sectional view taken approximately in the plane of line '55 of FIG. 1, this view showing a center-carrying block and the bar from which the block is suspended; and

FIG. 6 is a section taken approximately in the plane of line 66 of FIG. 5, this view showing spring means which acts on a center-carrying block, the block being omitted in this View for the purpose of clarity in illustration.

Generally, and as shown in FIGS. 1 and 2, the attachment of the invention includes a pair of coaxially arranged centers 10 and 10' adapted to support therebetween a workpiece 12. The centers 10, 10 are suspended from an elongated blade or bar 14. The bar 14 is supported by means A for turning movement of the bar toward and away fromwork-operating position. The bars ice work-operating position is indicated by the solid line showing in FIGS. 1 and 2, and out-of-work-operating or rest position by the dot-dash line showing of FIG. 2.

Means B is provided for removably attaching the barsupport means A to a centerless grinder and includes intermediate adjusting means C to permit the position of the bar support means to be adjusted in a pair of mutually perpendicular directions.

The work-supporting centers 10 and 10' are suspended from the elongated bar 14 by means D in the form of respective blocks 16 and 16 which are connected to the bar. The bar is provided with guide means E extending along the length thereof, the guide means permitting adjustment of the spacing between the blocks, and their respective centers. Resilient means F (FIGS. 2 and 6) urges the block 16 toward the block 16'. Manually operable means G connected to the bar 114 permits the bar, and the work-supporting centers 10, 10, to be moved from the rest position, as indicated by the dot-dash line showing of FIG. 2, to the Work-operating position, where the bar overhangs the work-engaging surfaces of a centerless grinders grinding and regulating wheels 15 and 17, as shown in FIG. 1. Means H (FIGS. 2-4) is provided to releasably hold the bar in its upward or rest position, and means I is provided to limit the downward movement of the bar to its Work-operating position.

in greater detail, and as shown in FIG. 1, the attaching means B includes a plate 18 removably connected to the infeed work-rest 2d of a centerless grinder. At its underside the plate 18 has a rib 22 adapted to be received in a mating groove formed in the work-rest. On its upper face the plate 18 is provided with a longitudinal groove 24. Adjacent its corners the plate 18 is provided with countersunk tapped holes 26, adapted to receive screws which extend into the work-rest to removably fix the plate 18 to the'machine.

The attaching means B further includes a plate 28 having a rib 30, which is adapted to be received in the groove 24. The plate 28 is fixed to the plate 18 by screws received in countersunk tapped holes 32 and extended into aligned tapped holes formed in the plate 18 adjacent the groove 24. The plate 28 is provided on its upper face with a longitudinally extending dovetail projection 34 which extends parallel to the axes of the grinding and regulating wheels 15 and 17.

While plates 18 and 28 may be made as one integral body, it is preferred to have separate plates. The plate 18 is light enough to permit it to be easily handled, and several plates 28 of different thickness may be provided to enable the operator, by choosing a plate 28 of a given thickness, to locate the remainder of the attachment at a selected elevation.

The attaching means B also preferably includes a carrier plate 40 to which the support means A is connected. The plate 40 forms, with the projection 34 and a dovetail groove 41 on the underside of support means A, the

' adjusting means C which permits adjustment of the support means A in a pair of mutually perpendicular directions, one of which is parallel to the axes of the wheels 15 and 17. Thus, the attaching means B guides plate 41) for movement in one direction parallel to the axes of the grinders wheels, and the plate 40 guides support means A for movement in a second direction perpendicular to such axes. For this purpose, the plate 40 is provided on its underside with a dovetail groove 43 which slidably receives and mates with the projection 34; and on its top side, the plate has a dovetail projection 42 which extends perpendicularly'to the projection 34, and which is slidably received'in and mates with the dovetail 41 on the underside of the support means A.

At its underside, the plate 40 is formed with a slit 44 which extends all the way across the plate, parallel and adjacent one side of the dovetail groove 43 to thereby form a springy tongue 46. The plate 46 also is formed with a plurality of tapped holes 48 communicating with the slit 44 and respectively receiving set screws which may be turned to press the tongue 46 against the projection 34, to furnish, with tongue 46, a means for releasably fixing the plate 40 to the plate 28 after suitable positioning of the parts.

The support means A is of generally U-shaped configuration. In the illustrated showing a pair of identically oriented angle members 50 and 52, one of which (member 52) is smaller than and fixed to the other (member 50) by screws 54. Offset dowels 56 are received in aligned apertures formed in the bases of angle members 50 and 52 so that member 52 may be precisely positioned with respect to member 50. While a unitary U-shaped body, cast or machined, may be used for the support means A, an assembly of angle members such as illustrated is preferred because such members and their arrangement are readily available, easily assembled, and inexpensive. The underside of member 50 is formed with the dovetail groove 41, which receives projection 42 of plate 40 as previously described.

The underside of angle member 50 is also formed with a slit 58 coextensive with and adjacent to the dovetail groove 41, and forming with one side thereof the springy tongue 60. Also, the member 50 is formed with tapped holes 62 communicating with the slit 58 to receive set screws which may be turned to engage and press the tongue 60 against the projection 42, thereby providing means for releasably fixing the support means A to the carrier plate 40.

The parallel, vertical walls of angle members 50 and 52 are respectively formed with coaxially arranged openings into which bushings 64 are press-fitted. The bushings receive and support for rotation a shaft 66 which extends across the space between the vertical walls.

As shown in FIGS. 1 and 6, the elongated bar 14 is provided with an enlarged end 68 which is received between and slidably engages the vertical walls of the angle members 50 and 52. The bars enlarged end is provided with a through hole 68 through which the shaft 66 extends with little, if any, clearance (FIG. 6). The bar 14 is fixed to the shaft 66. For this purpose, the shaft is provided with a short flat face portion 70, which is engaged by the inner end of a set screw 72 threaded into a tapped hole 73 formed in the enlarged end 68 of the bar. Thus, the bar 14 and the shaft 66 are fixed to each other and free to move together in rotation only. In this way the elongated bar 14 is swingably connected to a fixed support means A for turning movement between the positions shown by the solid and dot-dash lines in FIG. 2.

The end of shaft 66 which is visible in FIG. 2 extends beyond the vertical wall of angle member 50 and is received in the hub of a handle or hand-crank 74 which forms the manually operable means G. A cross pin 76 extends with a tight fit through a transverse bore in shaft 66, the ends of the cross-pin being respectively received in aligned openings in the hub of handle 74 to thereby fix the handle to the shaft. Thus, the operator may manipulate means G to move the elongated bar 14 between the work-operating and rest positions shown in FIG. 2.

As shown in FIGS. 1, 3 and 4, a detent adjusting or indexing disk 78 is rotatably mounted on the shaft 66 and located between the hub of the handle 74 and the exterior surface of the vertical wall of angle member 50. The disk has its center on the axis of shaft 66, and is provided with a plurality of arcuate slots 80 through which the shanks of screws 82 respectively extend into tapped holes formed in the Wall of member 50. The screws 82 have heads which are wider than the slots 80, and by loosening the screws the angular position of the disk 78 may be adjusted within the range permitted by the length of the slots, which are of equal length. Tightening the screws fixes the adjusted position of the disk. The disk is formed with an opening 84 which forms part of the detent means H.

The detent means H includes the spring-pressed pin 86 which is located in a bore formed in the hub of the handle '74 and is urged to the left, as viewed in FIGS. 3 and 4, into engagement with the outer wall of the detent disk 73. When the pin 86 is displaced from or is out of alignment with respect to the opening 84 (FIG. 3), the elongated bar 14 is in the solid-line or work-operating position shown in FIGS. 1 and 2. When the pin 86 is in its lower positicn and located in the opening 34 (FIG. 4), the bar 14 is in its upper or rest position as shown by the dot-dash lines in FiG. 2. The pin 86 is located at the same radial distance from the axis of shaft 66 as the opening 34. Because of the configuration of its left end or nose 87, the pin 86 will move out of the opening 84 when the operator applies an upwardly directed pressure to the handle 74. When the operator presses down on the handle the bar is raised from work-operating position and comes to rest above the grinding and regulating wheels when the pin 86 snaps into the opening 84. In this latter position, a work-piece may be replaced.

In order to change the angle or range of swing of the elongated bar 14 between its work-operating and rest positions, the set screw 72 is loosened and the bar is rotated to the position desired for rest position. The screws 82 are loosened, and the disk 78 is rotated to appropriately change the location of the opening 84 therein, the rotation of the disk being permitted to the extent allowed by the slots 86. The screws 72 and 82 are then tightened. By affording the described adjustment for changing the arc of rotation of the elongated bar, the attachment may accommodate work-pieces of different diameter, and the operator may change work-pieces at a distance from the grinding wheel to assure that his hands will be safe from injury.

The limiting means I is provided to permit adjustment of the lower or operating position of the elongated bar 14. As shown in FIG. 2, the limiting means I is in the form of a screw 88 threaded into the underside of the enlarged end 68 of the bar 14. The lower or head end of the screw engages the base of angle member 50 to limit downward movement of bar 14, which remains in its operating position because of its weight and the weight of the structure carried thereby. A lock nut 90 fixes screw 88 in its adjusted position. While the limiting means may be carried by the base of angle member 50, the illustrated structure is preferred, because the screw 88 is readily accessible for adjustment when the bar 14 is in its upper or rest position.

If it is desired to additionally or alternately limit the downward movement of the elongated bar 14, the bar may be provided with a downwardly directed extension 92 at its opposite or free end for engagement with a stationary block 94, as shown in FIG. 1.

As shown in FIG. 2, the centers 10 and 10' have shanks which are received in bores formed in the blocks 16 and 16', respectively, threaded counter-bores being provided to receive screws 96 and 96 to fix the centers to the blocks. The means E guides the blocks 16 and 16 for movement along bar 14, such guide means preferably being in the form of an integral dovetail projection 98 extending longitudinally along the bar 14. As shown in FIG. 5, the dovetail fits in mating grooves 99 formed in the side of each block near its upper end. Each block is formed adjacent the upper side of its dovetail groove 99 with a slit 101) extending across the block parallel to its groove and forming a springy tongue 192. A plurality of screws 104 are threadedly carried by each block to press the tongue 102 against the dovetail projection 98 to provide a fastening means for releasably fastening each block to the bar 14.

The spring means F resiliently urges block 16 and its center 10 against a work-piece 12. Spring means F includes a pair of springs 106 respectively located in bores 108 formed in end 68 of the bar 14. The springs respec- 'tively urge pins 110 to the position shown in FIG. 6. The bores are stepped to provide shoulders 109 respectively engaging collars 111 formed on pins 110 to limit their movement by the springs. One end of each spring is seated against a collar 111. The other end of each spring is engaged by a set screw 1 12. The set screws are threaded into tapped end portions of the bores 108 to permit the compression of the springs to be adjusted. The block 16 is located closer to the end 68 of bar 14 than the maximum distance that pins 110 can project beyond end 68 so that the force of such spring means may act on such block. Thus, when the operator shifts block 16 away from block 16 against the resilient pressure on block 16, only the screws 1-04 associated with block 16 need be loosened if a work-piece of the same length will replace the finished, externally ground piece.

It is believed that the advantages of the attachment of the invention will be apparent from the foregoing detailed description of a preferred embodiment thereof. When the attachment of the invention is used on a centerless grinder, the work blade of the centerless grinder is not used. The work is rotated by the regulating wheel, so that the dogs of a conventional external grinder are unnecessary. The regulating wheel maintains a constant pressure on the work while the work is fed into the grinding wheel. A steady rest, required when taking a heavy cut on an external grinder, is unnecessary when a heavy cut is taken on a centerless grinder with the attachment of the invention. The attachment of the invention can be used on all modern centerless grinders without losing any of the advantages thereof, such as fast stock removal, minimum wheel wear and minimum redressing of the wheel. The attachment is readily attached to and removed from a centerles grinder to afford accurate and eificient external grinding. The attachment is simple and rugged, and may be operated wth a minimum of skill on the part of the operator. The overhanging characteristic of the work-centers gives the operator a high measure of safety.

While a preferred embodiment of the invention has been specifically illustrated and described, it will be apparent that various modifications and changes may be made without departing from the spirit and scope of the invention as sought to be defined in the following claims.

1 claim:

1. An attachment for a centerless grinder to enable same to also function as an external grinder, said attachment comprising an elongated bar adapted to overhang the Work-engaging surfaces of a centerless grinders grinding and regulating wheels, a pair of work-supporting centers, means for suspending said centers from said bar, guide means provided by said bar to enable the adjustment of the position of at least one of said centers along the length of the bar, means for rotatably supporting said bar near one end thereof, whereby the bar may be swung to and away from work-operating position, and means for removably attaching said bar-supporting means to a machine including means for adjusting the position of the bar-supporting means in a pair of mutually perpendicular directions, one of which is parallel to the axis provided by the centers.

2. An attachment for a centerless grinder to enable same to also function as an external grinder, said attachment comprising an elongated bar adapted to overhang the work-engaging surfaces of a centerless grinders grinding and regulating wheels,a pair of work-supporting centers, means for suspending said centers from said bar, guide means provided by said bar to enable the adjustment of the position of at least one of said centers along the length of the bar, means for rotatably supporting said bar near one end thereof, manually operable means connected to said bar for swinging the bar to and away from work-operating position, means for limiting the downward movement of the bar, means for releasably holding the bar in its out-of-work-operating position, and means '6 for removably attaching said bar-supporting means to a machine including means for adjusting the position of the bar-supporting means in a pair of mutually perpendicular directions, one of which is parallel to the axis provided by the centers.

3. An attachment as set forth in claim 2, wherein the means for releasably holding the bar in its out-of-workoperating position includes means for adjusting the range of movement of the bar between work-operating and outof-work-operating positions.

4. An attachment for a centerless grinder to enable the same to function also as an external grinder, said attachment comprising a substantially U-shaped support, means for removably attaching the support to a machine, an elongated bar having one end thereof positioned between the arm portions of the U-shaped support and connected thereto for swinging movement of the bar in a substantially vertical plane to and from work-operating position where the bar may extend in a generally horizontal plane to overhang the work-engaging surfaces of a centerless grinders grinding and regulating wheels, said bar having guide means extending longitudinally thereof, a pair of blocks adapted to carry work-supporting centers, said blocks cooperatively engaging said guide means, means for releasably securing at least one of the blocks to the bar, detent means to releasably hold the bar in its out-ofwork position, and means for limiting the downward movement of the bar.

5. An attachment as set forth in claim 4, wherein an adjustably mounted disk is provided for cooperation with the detent means for adjusting the range of swing of the bar.

6. An attachment for a centerless grinder to enable same to also function as an external grinder, said attachment comprising an elongated bar adapted to overhang the Work-engaging surfaces of a centerless grinders grinding and regulating wheels, a pair of work-supporting centers, means for suspending said centers from said bar, resilient means for cooperation withmeans for suspending one of the centers from the bar for urging same toward the other center, guide means provided by said bar to enable the adjustment of the position of at least one of said centers along the length of the bar, means for rotatably supporting said bar near one end thereof, manually operable means connected to said bar for swinging the bar to and away from work-operating position, means for limiting the downward movement of the bar, means for releasably holding the bar in its out-of-work-operating position, and means for removably attaching said barsupporting means to a machine.

7. An attachment for a centerless grinder to enable the same to function also as an external grinder, said attachment comprising a substantially U-shaped support, means for removably attaching the support to a machine, an elongated bar having one end thereof positioned between the arm portions of the U-shaped support and connected thereto for swinging movement of the bar in a substantially vertical plane to and from work-operating position where the bar may extend in a generally horizontal plane to overhang the work-engaging surfaces of a centerless grinders grinding and regulating wheels, said bar having guide means extending longitudinally thereof, a pair of blocks adapted to carry work-supporting centers, said blocks cooperatively engaging said guide means, means for releasably securing at least one of the blocks to the bar, the end of the bar adjacent the U-shaped support being provided with resilient means for engagement with a block to urge same toward the other block, and means for limiting the downward movement of the bar.

8. An attachment for a centerless grinder to enable the same to function also as an external grinder, said attachment comprising a substantially U-shaped support, means for removably attaching the support to a machine, an elongated bar having one end thereof positioned between the arm portions of the U-shaped support and connected thereto for swinging movement of the bar in a substantially vertical plane to and from Work-operating position Where the bar may extend in a generally horizontal plane to overhang the work-engaging surfaces of a centerless grinders grinding and regulating wheels, said means for removably attaching the support to a machine including means for adjusting the position of the support in a pair of mutually perpendicular directions, one of which is parallel to the direction in which the bar extends when in work-operating position, said bar having guide means extending longitudinally thereof, a pair of blocks adapted to carry Work-supporting centers, said blocks cooperatively engaging said guide means, means for releasably securing at least one of the blocks to the bar, and means for limiting the downward movement of the bar.

References Cited in the file of this patent UNITED STATES PATENTS 1,363,194 De Koning Dec. 21, 1920 1,367,522 Bernard Feb. '1, 1921 2,122,184 Scrivener June 28, 1938 2,443,719 Beubel June 22, 1948 FOREIGN PATENTS 537,980 Germany Nov. 9, 1931 

1. AN ATTACHMENT FOR A CENTERLESS GRINDER TO ENABLE SAME TO ALSO FUNCTION AS AN EXTERNAL GRINDER, SAID ATTACHMENT COMPRISING AN ELONGATED BAR ADAPTED TO OVERHANG THE WORK-ENGAGING SURFACES OF A CENTERLESS GRINDER''S GRINDING AND REGULATING WHEELS, A PAIR OF WORK-SUPPORTING CENTERS, MEANS FOR SUSPENDING SAID CENTERS FROM SAID BAR, GUIDE MEANS PROVIDED BY SAID BAR TO ENABLE THE ADJUSTMENT OF THE POSITION OF AT LEAST ONE OF SAID CENTERS ALONG THE LENGTH OF THE BAR, MEANS FOR ROTATABLY SUPPORTING SAID BAR NEAR ONE END THEREOF, WHEREBY THE BAR MAY BE SWUNG TO AND AWAY FROM WORK-OPERATING POSITION, AND MEANS FOR REMOVABLY ATTACHING SAID BAR-SUPPORTING MEANS TO A MACHINE INCLUDING MEANS FOR ADJUSTING THE POSITION OF 